Power driven open-end ratcheting wrench



June 21, 1955 A, J, BRAME 2,711,110

POWER DRIVEN OPEN-.END RATCHETING WRENCH Filed oct. 8, 1952 2sneek-sheet 1 ATTORNEYS June 2l, 1955 A, Jl BRAME v 2,711,110

POWER DRIVEN OPEN-END RATCHETI'NG WRENCH Filed oct. s, 1952 K 2sheets-sheet 2` l 25 FIG. 5.r

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IN VENTOR ALLEN J. BRAME MTORNEYS United States Patent 0 POWER DRIVENOPEN-END RATCHETING WRENCH Allen J. Brame, Los Angeles, Calif., assignorto Tubing Appliance Company, Inc., Los Angeles, Calif., a corporation ofCalifornia Application October 8, 1952, Serial No. 313,728

17 Claims. (Cl. 8158.1)

This invention relates to improvements in open-end ratcheting wrenchesof the general type exemplied in my copending applications Serial No.261,103 tiled December 1l, 1951 and Serial No. 300,260 filed Julyv22,1952 and in the patent to Fish No. 2,578,687.

More particularly, the invention relates to improved wrenches of thegeneral type indicated above, the improved wrenches being especiallyalthough not exclusively adapted to be power driven.

An object of the invention is to provide improved openend wrenches whichembody the structurally advantageous features of the above mentionedtype of wrenches together with the functionally advantageous featuresthereof and which involve improvements in the forms and relativearrangements of their components, which endow the improved wrenches withgreaterfruggedness mechanic can rotate nuts on tubing, conduit, cable,shaftl;

ing and the like to which the wrench is applied, with greater facility,ease, and eciency than heretofore attainable, and complete thetightening of a nut or the like much more quickly.

lt is also an object of the invention to provide an irn-` provedpower-driven wrench of the character Vindicated above wherein thehousing or head is composed of two substantially similar stampedsections or halves, each having registered lateral flanges which formthe sidewalls of ,g wrenches.

the housing or head when the sections are assembled, and registeredextensions which form the bearing support or enclosure for the actuatingshaft bearing when the sections are assembled.

A further object of the invention is the provision of i an improvedwrench of the character indicated above wherein flanges are provided onthe assembled sections for a hub carrying the work gripping component orwrench socket, one of the flanges being a shear ange and another a guideflange, the hub being formed inopposite sides with arcuate concentricgrooves which receive the anges, whereby the hub is positively guidedthe line 4&4 of Figur 3S 2,711,110 Patented June 21, 1955 head orhousing, and `Vthe sectionassembling or fasten'- ing means.

A further object of the invention is' to provide im= proved power-drivenopen-end ratche'ting wrenches which are driven or operated by axiallyrotated power driven actuating shafts, journalled in bearing meanssupported and housed within a portion of housings enclosing the ratchetmechanism and Aconstituting the heads of the wrenches, the actuatingshafts being located in a plane substantially parallel-to and locatedbetween'the webs of the housing sections and being preferably radialwith respect to the geometric center of the head or housing, so that thewrenches have atand low profiles enabling reaching and turning nutsvonpipe or the like through conned spaces not much wider than the thicknessf the heads or housings of the wrenches and not much longer than thewidth of the heads or housings.

Av still further object of the invention involves the pro vision of animproved wrench of the character indicated above in which an axiallyrotatable actuating shaft care ries an eccentric or rotary cam withinthe housing or head which is operatively engaged with the ratchet pawlcarrier for operating the ratchet pwl carriernr one direction.

Another object of the invention is the provision of improved wrenches ofthe character indicated Vabove wherein the axially rotatable actuatingshaft is positioned radl= ally with respect to the center of curvatureof the arcuate path of movement of the ratchet pawl carrier whosearcuate movement produces arcuate movement of a hub on which the workengaging member is mounted.

Still another object of the invention is to provide im`- proved wrenchesof the character indicated above wherein the rotary actuating shaft ispositioned radially also with respect to the center of curvature of thearcuate path of movements of the ratchet pawl carrier and the hub, andthe shaft is positioned substantially in the same' plane as the ratchet,carrier and the hub.

A further object of the invention is to provide improved Wrenches of thecharacter indicated above which can be fabricated and assembled at acost much less than the wrench of the herein mentioned Fish patent, andwhich can more than adequately replace present open-end wrenches, andwhich can, by proper heat treatment of the stamped housing sections `andother components of the wrench, take greater working loads than presentA still further object of the invention is to provide a preferablypower-driven open-end ratchet wrench of Vthe' general. characterindicated above wherein the head or' housing is composed of twosuperimposed stamped sections, the lower section being hollow and openat its to`p` and containing the hub, tlie hub guiding means, the ratchetmechanism, and the tubular carrier, or enclosure forthe bearing of theactuating shaft and being the load bear'-` ing section, the other orupper head or housing section 53 being in the fonn of a at plate servingas a cover for the open upperV end of the lower section and servingmerely as a retainer for certain of the components within the hollow'lower section.`

' Other important objects and advantageous features of,l the inventionwill be apparent from theffollowing d'escription and the accompanyingdrawings, whereimfor purposes of illustration only, specific embodimentsof the invention are set forth in detail.

In` the drawings:

Figure 1 is a side edge elevation of an embodiment;

Figure 2 is atop plan view thereof;

Figure 3 is a plan view with the upper housing or head section removed;

Figure 4 isa vertical longitudinal section taken on Figure 5 is atransverse vertical section taken on the line 5 5 of Figure 4; e

Figure 6 is a fragmentary transverse vertical Sectio taken on the line6-6 of Figure 3;

Figure 7 is a fragmentary transverse vertical section taken on the line7 7 of Figure 3;

l Figure 8 is a fragmentary transverse vertical section taken on theline 8 8 of Figure 3;

dFigure 9 is a top plan view of another embodiment; an

Figure 10 is a vertical longitudinal section taken on the line 10-10 ofFigure 9.

Referring in detail to the drawings, wherein like numerals designatelike parts throughout the several views, and irst to Figures l to 8, theopen end ratcheting wrench therein shown and generally designated A,cornprises a head or housing composed of a pair of superimposed andregistered head or housing sections 16 and 17, hereinafter convenientlyreferred to as the upper and lower head or housing sections,respectively, and as the retaining section and load bearing section,respectively.

The sections 16 and 17 consistof substantially identical stampings ofgenerally oval shape in plan, each involvingV a plain flat web 18 havingthereon a lateral peripheral flange 19 extending therearound. Thesections are provided in one end, hereinafter conveniently referred toas the forward end, with registering longitudinal slots which togetherform a mouth 20 which opens into a circular' hub receiving opening 21which extends through both sections. the flanges 19 abut and, as shownin Figure 1, a linger 22 on the upper section 16 engaging a recess 22 onthe lower section 17 facilitates orientation of the-sections in beingassembled and keeps the sections from shifting out of registery.

Bolts or rivets 23, 23 are passed through peripheral portions of thesection Webs 18, as shown in Figures 2 and 7, for holding the assembledsections together, the heads of the fasteners preferably being locatedin depressions ordimples 24, 24 in the webs to avoid projection of theheads beyond the outer faces of the webs 18, 18.

The webs of the sections are distorted at points adjacent to their rearends to provide arcuate clearance chambers 25, 25 which extendlongitudinally and centrally of the sections and provide roorn foroperation of an eccentric or rotary cam hereinafter described.

Semi-cylindrical extensions 26, 26 arranged longitudinally preferably onthe center lines of the sections 16 and 17 project rearwardly from therear ends of the sections and register to form a cylindrical actuatingshaft bearing support or enclosure 27. An assembling ring 28 encirclesthe extensions 26, 26 and serves to hold the extensions together and insupporting relation to the outer race 29 of an annular actuating shaftbearing 3i) positioned longitudinally in the enclosure 27, preferably inaxial alignment with the longitudinal center lines of the sections 16and 17, and preferably axially aligned with a longitudinal line throughthe housing or head 15 which is midway between and parallel to the webs18 of the sections.

As shown in Figure 4, the bearing 30 is preferably a needle-type rollerbearing, and is held in place in the enclosure 27 by suitable means,such as the retaining ring 31. An actuating shaft 32 extends axiallythrough the inner race 33 of the bearing 30 and projects into theinterior of the housing 15 at the rear end` of the housing.

The outer or rear end of the actuating shaft 32 is adapted to beconnected in a suitable manner (not shown) to means for rotating theshaft, preferably a motor or other power take-off (not shown).

The inner or forward end 34 of the actuating shaft 32 which projectsinto the rear part of the interior of the housing 15 is eccentric withrespect tothe axis of the shaft 32. On the eccentric shaft end 34 isixed the inner race 35 of a rotary carn bearing 36, preferably a needle-In their assembled relation, the free edges of 4 type roller bearing.The outer race of the cam bearing 36 is in the form of a cam ring orface 38. A retaining i ring 39 is seated in a groove 40 in the eccentricshaft end 34 for holding the bearing 36 in place between the ring 39 andan annular thrust shoulder 37 formed on the shaft 32 at the rearward endof the cam bearing 36, as shown in Figures 3 and 4.

A ratchet pawl carrier 41 is positioned within the housing 15 in thespace between the rotary eccentric cam tively deep depending rightangular flange 43 which is' arcuate in horizontal cross section so as toconformably and slidably bear against the rearward side, constituted byan annular row of ratchet teeth 44, of a substantially v semi-circularrotary hub 45. On its yforward edge the carrier plate 41 has arelatively shallow depending arcuate guide flange 46 which engagesdownwardly in an arcuate guide groove 47 provided in the hub 45. The topsurface 48 of the carrier plate 41 is slidably engaged by the underfsurface of the web 18 of the upper housing section 16; as shown inFigure 4, and is thereby held down in place in operative engagement, asabove described, with the hub 45. .The carrier plate 41 operates in aplane parallel lto the webs 18 of the housing sections and parallel tothe axis of the cam ring 38 and the actuating shaft 32.

Operative connection between the carrier plate 41 and the rotary camring 38 is provided by a earn lobe or v follower 50 which is in the formof a nger projecting rearwardly from the rearward edge of the carrierplate" 41 at a slightly obtuse angle to the axis of the. rotary cam. Thefollower 50 terminates at its free end in' a cam surface or end 51conformably engaging the periph-l eral surface of the cam ring 38.Expanding compressible helical springs 52, 52 are compressed betweenlugs 53,. 53 on the sidewall of the housing 15, defined by the sectionflanges 19 and portions on the upper and lower-V sides of the camfollower 50. The springs 52 are located in the housing 15 at the sameside of the cam as the cani follower and serve to yieldably maintain thecam surface 51 in constant engagement with the peripheral' surface ofthe cam ring 38. The arrangement of the K springs 52, 52 atand in thrustengagement with the carrier plate/41 at opposite sides' of the carrierplate 4i.l

serves to stabilize and case the operation of the carrier plate and tomaintain constant the predetermined angle of engagement of the camfollower with the cani.

lt will be obvious from the foregoing that upon rotation of theactuating shaft 32, by suitable means, the eccentric rotation of the camwillproduce reciprocalion of the carrier plate 41 crosswise of thehousing aud back and forth along the row of ratchet teeth 44 on the hub45, and in so doing produce step-by-step rotation annulus 58 which isformed with the aforementioned` ratchet teeth 44. The upper and lowersides ofthe toothed annulus 58 are axially spaced from vthe edges 56 and57, respectively, of the annulus 55. The upper.

side of the toothed annulus 58 contains the guide groove 47l which visengaged bythe vshallow'er `ange 460i thecarrier plate 41. The lower sideof the toothed annulus 58 is provided with an arcuate load carryinggroove 61 registering with and coextensive with the guide groove 47. Theload carrying groove 61 engages an arcuate load carrying or shear iiangeor rib`62 which is formed on and projects upwardly from the web 18 ofthe lower housing section 17, as shown in Figure 4. The hub 45 isthereby stabilized in the housing 15 and eased in its rotation relativethereto. In addition, the conf forming and closely .slidinginterengagement of the grooves 47 and 61 of the toothed annulus 58, withthe flanges 43 and 46 of the ratchet pawl carrier plate 41, and theengagement of the hub and the carrier plate with the webs 18 of thehousing sections together elimi nate twisting and shearing strains uponthe moving parts and transmit or transfer all shearing' stressesdirectly and almost exclusively to the housing and to the fasteners 23securing the housing sections together. Further, and importantly,through the engagement of the load carrying groove 61 and load carryingiiange 62, the lower housing section is made to serve as the loadcarrying member of the wrench. The load carrying flange 62 is arcuateand extends around the circular opening 21 of the housing 15 in whichthe hub 45 rotates. The ratchet pawl carrier guide flange 46 is similarto the load carrying fiange 62 and is opposed to the load carryingflange 62 and is engaged in the groove. 47 of the hub 45. Because ofthis the iianges 46' and 62 actas oppositely directed shear iiangeswhich support the hub in its rotative movements occurring in the. useand operation of the wrench. The forces thus introduced into the wrenchare transmitted from the hub 45 to the lower housing section 17 and tothe ratchet pawl car` rier 41 when a torsional moment is applied to anut engaging member, such as the member 67, heldby the hub 45. Themoments applied to the pawl` carrier 41 by the pawls 42, 42 are takenout through the flange 46 and groove 47, forming parts of `hubreinforcing means.

The upper housing section 16 carries practically no loads and actsmerely as retaining and positioning means for the hub 45 and pawlcarrier 41, the only moments applied to the upper housing section -I6occurring by the action of the pawl carrier 41 as it is moved-first bythe cam 36 and then by the springsv 52, S2 in oppo site directions. l

The annulus of the ratchet wheel or hub 45,1ike. the hubs or ratchetwheels of the above mentioned copending applications, is formed with adiametrical slot arranged to be registered with the mouth 20 intheforward end of the head or housing 15 in an appropriate. rotatedposition of the hub 45. .The hub 45 has an axial opening or concavesurface whereby the hub serves as a socket receptor for a conformingshank 66 of any selectedwork-engaging member,` such as the semi-annularsocket 67. The semi-annular shan-k 66 terminates at its ends in radiallydisposed abutments or. drive shoulders 68, 68 for engagement withhook-shaped abutments or shoulders 69, 69 formed on the ends of the hub45, as shown in Figures 2 and 3, whereby upon rotation of the hub 45 ineither direction the shank 66 of the socket 67will be positivelyrotated.

The concavesurface 65 of the hub 45 is provided between its ends with aspring pressed ball detent 70 arranged for retaining engagement with a4complementary recess 71 provided in the socket shank 66 so as to preventaxial displacement of the socket 67 relative to the huby 45 when inplace therein.

Referring nowy to Figures 9 and i0 of the drawings, themodified formofthe invention shown` thereinand gen-v erally designated B, operateslike form A, but differs from form A described hereinabove in thestructure of the housing 75.. Instead of the. housing 75 being corn.-vposed of two similar housing sections, the housing 75; is composed of arelative deep lower or load bea-ring.

housing section .77, and an upper or retaining housing section 76 whichserves as a cover for the open upper end of the lower section 77.Further, 'the actuating shaft bearing enclosure 87 of the modified formB is formed entirely on the lower housing section 77.

The upper or cover housing section 76 comprises a flat plate `88 whichin plan shape is substantially like the web Y18 of the upper housingsection 76 of the first described form of the invention, and conformablyts into the open upper end 89 of the lower housing section 77. The plate88 has a depending enlargement 90 in its underside which bears upon thetop surface of the ratchet pawl carrier plate 41, as shown in Figure'10. The cover plate 88 is held down in place by fasteners 23 engagingthe lower housing section 77.

I claim: l l. In a wrench, a head comprising a housing provided with anopening for accommodating a work-engaging element, said housing beinghollow and composed of a retaining section and a load bearing section,means securing said sections together in superimposed relation, saidload bearing section being hollow and having an open side facingrsaidretaining section with the retaining section closing said open side, ashear fiange on said load bearingsection, said shear fiange beingarcuate and extending around said opening, a rotary hub having a portionwithin said housing and operatively engaging said shear ange and aportion exposed in said opening for operative engagement with a workengaging element located in said opening, said retaining section, havinga portion sIidably engaging said hub, and serving to hold said hub inengagement with said shear iiange, and actuatingmeans on said housingand operatively connected to said hub for rotating the hub along andrelative to said shear liange.

2. A wrench'according to claim 1 wherein said retaining section ishollow and has an open side facing said load bearing section.

3.`A wrench according to claim l wherein said retaining section ishollow and has an open side facing said load bearing section, saidretaining and load bearing sections being substantially similarly shapedstampings.

4. A wrench according to claim 1 wherein said actuating means comprisean actuating shaft extending radially with respect to the housing andprojecting from the housing, at least one of the sections having aradial extension defining a bearing enclosure, and a bearing confinedwithin said bearing enclosure and supportably surrounding saidactuatingshaft.

5. A wrench according to claim 1 wherein said actuating means comprisean actuating shaft extending radially with respect to said housing andprojecting from the housing, s aid retaining section and said loadbearing section having registered extensions together defining a bearingenclosure, a bearing confined in said enclosure and supportablysurrounding said actuating shaft.

6. A wrench according to claim l wherein said actuating means Vcomprisean actuating shaft extending radially with respect to said housing andprojecting from the housing, said load bearing section having a tubularextension defining a bearing enclosure, a bearing confined in saidenclosure and supportably surrounding said actuating shaft.

7. In a wrench, a head having a work receiving opening, a hub on saidhead,r guide means on said` head confining said hub to movement in afixed path around said opening, said hub having a row of ratchet teeth,a carrier plate mountedy on saidl head for movement along said row ofratchet teeth in aplane parallel to that in which said hub moves, atleast one ratchet pawl pivoted on said carrier plate, first spring meansacting between said carrier plate and said ratchetv pawl and yieldablyengaging said ratchet pawl with said rowvof ratchet teeth, a camfolloweron said carrier plate, an actuating shaft journalled on said head, avrotary cam fixed on said actuating shaft and engaging said camfollower, second spring means acting between said head and said carrierplate and urging said carrier plate in a direction to keep said camfollower engaged with said rotary cam, said actuating shaft and saidrotary cam being positioned with their axes in planes parallel to theplane in which the carrier plate moves, and means connected to saidactuating shaft for rotating said shaft in a direction to move said hubaround said opening.

8. In a wrench, a housing having a work receiving opening, a hub mountedon said housing for movement around said opening in an arcuate path,ratchet teeth formed on said hub, said ratchet teeth being arranged inan arc, a carrier mounted on said housing for movement relative to saidhub in a path substantially concentric with the arc of the ratchet teethon the hub, at least one spring pressed ratchet pawl pivoted on saidcarrier and engaging the arc of teeth on the hub, a cam follower on saidcarrier, a rotary cam mounted on said housing and engaging said camfollower, and means for rotating said cam. v

9. In a wrench, a head having a work receiving opening, a hub mounted onsaid housing for movement around said opening, said hub having a row ofratchet teeth thereon, a carrier mounted on said head for movementrelative to said hub and along said row of ratchet teeth, said carrierhaving at least one spring pressed ratchet pawl thereon engaging saidrow of teeth, a'cam follower on said carrier, a rotary eccentric cammounted on said head and engaging said cam follower, return spring meansacting between said carrier and said head serving to hold the camfollower yieldably engaged with said rotary cam, and an actuating shaftjournalled on said head and carrying said rotary cam, said shaft androtary cam being positioned in planes parallel to the plane in whichsaid carrier moves.

10. ln a wrench, a head comprising a hollow housing comprising twosimilar sections involving websand peripheral, lateral flanges on thewebs, means securing the sections together with their lateral angesregistered and abutted so as to dene sidewalls extending between saidwebs, said sections having concave extensions on one end thereof whichare in registry and dene a hollow bearing enclosure, the end of saidhousing remote from said bearing enclosure being formed with a workreceiving opening, a rotatable hub having a gripping portion outside ofsaid housing and another portion projecting into the interior of thehousing, guide means on said sections engaging said other portion andconfining said rotatable hub to a predetermined path of movement aroundsaid opening, said other portion of said hub having a row of ratchetteeth thereon on the side thereof remote from said gripping portion, acarrier plate within said housing, means confining said carrier plate tomovements along said row of ratchet teeth in a plane located between andparallel to the webs of the sections, at least one ratchet pawl pivotedon said carrier plate, rst spring means acting between carrier plate andsaid housing and urging said ratchet pawl into engagement with said rowof ratchet teeth, a cam follower on said carrier plate, a bearingenclosed in said bearing enclosure, a rotary actuating shaft extendingthrough said bearing and into the interior of the housing, an eccentricrotary cam fixed on the part of the actuating shaft within the housing,said cam being engaged with said cam follower, spring means actingbetween said carrier plate and said housing and maintaining said camfollower yieldably engaged with said rotary cam, said bearing and saidactuating shaft being positioned with their axes parallel to the webs ofthe sections and normal to the housing sidewalls.

Cir

ll. In a ratcheting wrench, a head comprising a hollow housing providedwith an opening for accommodating a work engaging element and with aslot in one end of the housing communicating with said opening toA admita ywork-piece into said opening, a tubuiar bearing enclosure projectingradially outwardly from the other end of the housing, a bearing enclosedin said enclosure, a rotary actuating shaft extending axially throughsaid bearing and having one end within said housing, a rotary eccentriccam on said one end of the shaft, a carrier plate mounted Within saidhousing for movement in an arc substantially concentric with saidopening, spring pressed, ratchet pawls pivoted on said carrier plate, acam follower on saidicarrier plate engaging said rotary cam, springmeans acting between said carrier plate and said housing serving tomaintainV constant engagement of said cam follower with said Vro'- tarycamysaid housing having spaced parallel webs including a retaining weband a load bearing web between which said carrier plate is positioned, asemiannular rotary hub positioned Within and concentric to said opening,said hub having an arcuate portion positioned in the housing betweensaid webs, said arcuate portion having sides spaced from said webs, the

side of said arcuate portion adjacent to said retainingA web beingprovided with an arcuate guideV groove and said carrier plate having aguide ilange' positioned in said guide groove, said retaining web beingengaged with` said carrier plate and coniining said guide ange in said'guide groove, the side of said arcuate portion adjacent to the loadbearing web being provided with an arcuate load bearing groove, saidload bearing web having an arcuate shear flange engaged in said loadbearing groove, said load bearing web beingV engaged with the adjacentside of said arcuate portion, said arcuate shear flange being concentricwith and extending around said opening, and ratchet teeth on the side ofsaid arcuate portion of the hub adjacent to said carrier plate with' Iwhich said ratchet pawls are operatively engaged.

i2. A ratcheting wrench according to claim 11 where,-

in said housingis composed ofa load bearing sectionl .Y containing saidload bearing web and a retaining section containing said retaining web,and said bearing enclosure comprises registered extensions on saidsections.

13. A ratcheting wrench according to claim 1l wherein said housing iscomposed of Va load bearing section containing said load bearing web andsaid arcuate shear flanges and a retaining section containing saidretaining web, and said bearing enclosure consists of a tube xed on saidload bearing section.

14. A wrench of the type described, comprising: a I

head; a hub; support means for mounting said hub o n said head forrotative movement; an annular series of ratchet teeth formed onisaidhub; a pair of oppositely directed pawl means; a carrier member mountedfor arcuate movement on said head in a path concentric with said annularseries of ratchet teeth; means for pivotally mounting said pawl means onsaid carrier for `engagement with said ratchet teeth;A an eccentricrotary cam mounted on said housing and engaging said carrier; and meansfor rotating said cam whereby said carrier is arcuately moved to causesaid pawl means,

-.l' engaged with the ratchet teeth, to rotatably drive said Y hub. i

l5. A wrench, comprising: a housing having a wor receiving opening; ahub rotatable in said housing, said Y.

to be mounted on said hub; means forming a driving-- connection betweenthe nut engaging member and said hub, whereby said member is rotatablydriven with said hub; a plurality of ratchet teeth circumferentiallyformed on said hub; a pawl carrier mounted on saidV housing for arcuatemovement in a path substantially concen- Y n' tric with saidcircumferential ratchet teeth; a pairiof l pawl means carried by saidpawl carrier spaced cir- 1 cumferentially of said hub and engageablewith said ratchet teeth; and means including an eccentric cam engagingsaid carrier for intermittently moving said pawl carrier in oppositedirections along said arcuate path whereby said pawl means alternatelyoperates to drive said hub.

16. A wrench of the type described, comprising: a head having a workreceiving opening; a hub; means carried by said hub and interengagingwith means of said head for mounting and supporting said hub on saidhead for rotative movement; a replaceable nut en gaging member; meansfor mounting said nut engaging member on said hub for rotative movementtherewith; an annular series of ratchet teeth formed on said hub; a pairof oppositely directed pawl means; a carrier member mounted for arcuatemovement on said head in a path concentric with said annular series ofratchet teeth; means for pivotally mounting said pawl means on saidcarrier; resilient means holding said pawl means in engagement with saidratchet teeth; an eccentric rotary cam mounted on said housing andengaging said carrier; and shaft means adapted to be connected to apower source for rotating said cam whereby said carrier is arcuatelymoved to cause said pawl means, engaged with the ratchet teeth, torotatably drive said hub and the nut engaging member mounted thereon.

17. A wrench of the type described, comprising: a head; a hub; supportmeans for mounting said hub on said head for rotative movement thereon;an annular series of ratchet teeth formed about the periphery of saidhub; a carrier member; means on said carrier member coacting with meanson said hub for mounting said carrier member for arcuate movement withinsaid head in a path concentric with said annular series of ratchetteeth; at least one pawl mounted for pivotal movement on said carriermember; a spring element holding the pawl in engagement with saidratchet teeth; and means including an eccentric cam engaging saidcarrier member for intermittently moving said carrier member in oppositedirections along said arcuate path whereby the pawl engaged with theratchet teeth rotatably drives said hub.

References Cited inthe file of this patent UNITED STATES PATENTS Fish`Dec. 18,

